Biologists believe that this autophagy in octopuses is a sort of a disease that makes them behave in such a manner.
Why does an Octopus eat itself?
They researched that such behaviour takes place when an octopus is extremely hungry. Not only that, some octopuses ate themselves because they were stressed due to being in captivity. A stressed animal is most prone to infections. A bacterium that manages to take hold of the octopuses mind when stressed causes this act of horror.
Once such behaviour starts, it is difficult to stop. It even spreads to any other octopus that comes in contact with the one who has eaten its own limb!
The octopus eats itself in a horrible way and then within a few days it dies, succumbing to injuries caused by it. This happens to a captive octopus. But usually an octopus that is not in captivity and had eaten a limb can regrow a fresh new limb. Most probably in captive situations, the water gets infected which causes the death.
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